Kinetic analysis and pyrolysis characteristics of coconut shells at different heating rates

The pyrolysis characteristics and kinetics of coconut shells were investigated via thermo-gravimetric analysis (TGA) at different heating rates (5, 20, 40℃/min), and the pyrolysis mechanism was explored. The distributed activation energy model (DAEM) was used to study the pyrolysis kinetics. The experimental results reveal that the pyrolysis process includes three stages: dehydration, rapid pyrolysis and slow weight-loss. When heating rate increases, the maximum rates of mass losses increase clearly and yield of chars decreases. N2 adsorption isotherms of chars prapared under different pyrolysis temperatures show that the higher pyrolysis temperature is, the more developed chars’ microporosity is. When the weight loss rate attains between 0.1 and 0.8, the activation energies of samples are between 146－444 kJ/mol, whose curves are not monotonously increasing, but show “N” shape, The distribution function of activation energy reveals changes of the reaction properties of mass in different stages of pyrolysis, which helps to investigate the pyrolysis mechanism of coconut shells.